Petra Diamonds halts Williamson mine in Tanzania after dam breach

Dump trucks at the Williamson diamond mine. (Image courtesy of Petra Diamonds.)

Petra Diamonds (LON: PDL) said on Monday it had halted operations at its Williamson mine in Tanzania after a tailings storage facility burst, causing flooding in nearby areas.

The company, which also operates three mines in South Africa, said the eastern wall of Williamson’s tailing dam was “breached”, but said in an email that the pit was not affected.

Petra noted that there were no injuries or fatalities confirmed so far, adding that the government and mine emergency response teams had been mobilized to the site.

“While no injuries have been reported, any impact on the local communities would be viewed as a material negative from an ESG standpoint,” Berenberg bank analysts said in a note.

The diamond miner has worked hard to clean up its image in Tanzania. Last year, it achieved a £4.3 million (about $4.9m) settlement with claimants alleging widespread human rights abuses, including beatings and detentions, at Williamson —the country’s biggest diamond mine.

Petra, which has repeatedly denied the involvement of its own employees in the incidents, admitted that “regrettable” incidents took place at the mine in the past. 

The clashes between locals and police resulted in “the loss of life, injury and the mistreatment of illegal diggers” within the mining license, it said last year.

Watchdog World Mine Tailings Failures (WMTF) said Williamson’s is the third diamond tailings failure in a year and the 19th of this decade (2015-2024).

The organization’s executive director, Lindsay Newland Bowker, noted that in terms of mineral production, this decade is already the worst in terms of catastrophic tailings failures in recorded history.